I am Sam Altman, lead investor in reddit's new round and President of Y Combinator. AMA!
EDIT: I have to go do my class at Stanford (http://startupclass.samaltman.com; Paul Graham is speaking today), but will try to answer more questions later this afternoon!
EDIT 2: Back.
EDIT 3: Ok, I have to go to five hours of non-stop meetings, so I'm going to sign off. Thanks for reading!
I put up a blog post here: http://blog.samaltman.com/reddit
TL;DR: I'm investing (along with many others) in reddit.
We're working on a way to give 10% of our shares from this round to the reddit community. I hope we can increase community ownership over time--I've always thought communities like reddit should mostly own themselves, and that it's time for some innovation around corporate structure here.
I'm giving the company a voting proxy on my shares.
Also, I'm the President of Y Combinator (though this was a personal investment, not a YC one). Startups like Airbnb, Dropbox, Stripe, and many others (including reddit itself!) have gone through our program. I'm happy to answer questions about startups in general.
Excited to be along for the journey!
Leaving the reddit office after our first meeting: https://twitter.com/sama/status/489593535083999232